Added unit tests for the file locking function

src/util/io.rs

@@ -8,9 +8,54 @@ pub fn is_file_locked(filepath: &str) -> bool {
     .expect("Failed to execute command");
 
   let results = &String::from_utf8_lossy(&cmd.stdout);
+  println!("{}", results);
   if results.contains(filepath) {
     return true;
   }
 
   return false;
 }
+
+#[cfg(test)]
+mod tests {
+  use std::fs;
+  use std::mem::drop;
+  use std::path::Path;
+
+  use super::*;
+
+  #[test]
+  fn file_should_not_be_locked() {
+    setup("test-not-locked.txt");
+    assert!(!is_file_locked("test-not-locked.txt"));
+    teardown("test-not-locked.txt");
+  }
+
+  #[test]
+  fn file_should_be_locked() {
+    setup("test-locked.txt");
+    let path = Path::new("test-locked.txt");
+    match fs::File::open(&path) {
+      Err(e) => panic!("couldn't open {}: {}", "test-locked.txt", e),
+      Ok(_) => assert!(is_file_locked("test-locked.txt")),
+    };
+    teardown("test-locked.txt");
+  }
+
+  // get things ready for our tests
+  fn setup(test_file: &str) {
+    let f = match fs::File::create(test_file) {
+      Ok(file) => file,
+      Err(e) => panic!("{:?}", e),
+    };
+    drop(f);
+  }
+
+  // clean up after running tests
+  fn teardown(test_file: &str) {
+    match fs::remove_file(test_file) {
+      Ok(_) => {},
+      Err(e) => panic!("{:?}", e),
+    };
+  }
+}